1. Field of the Invention
The present invention relates, in general to dispensing devices and, more particularly, to dispensing devices for flowable food products such as coffee or similar material.
2. Statement of the Problem
Many products are benefited by storage in a vacuum or reduced pressure environment until they are used. This is particularly true of many food products and especially true of roasted coffee beans. Coffee beans are known to lose their aroma, flavor, and essential oils when stored for even short periods of time at standard atmosphere pressure. Coffee beans are negatively affected by humidity and moisture in the air also. This is why coffee manufacturers have shipped coffee in vacuum packed canisters in order to preserve flavor and freshness and increase shelf life of the coffee. While simply storing the product in a sealed container at atmospheric pressure helps preserve the product, it has long been known that vacuum storage is preferable.
Roast coffee bean sales are a growing portion of the coffee market. Coffee tends to lose flavor more quickly once ground. Consumers who recognize this tendency purchase coffee beans rather than ground coffee. The consumers grind the coffee beans as needed to provide the ultimate in freshness. This also allows the consumer to blend the coffees to suit their particular taste by mixing grinds from selected varieties and roasts of beans. While coffee beans are less susceptible to flavor loss than is ground coffee, loss of flavor due to storage at atmospheric pressure is still a major concern for coffee distributors.
A popular way to store and dispense fresh roasted coffee beans is at the retail level by providing a dispenser on a supermarket or cafe shelf that the consumer can use to select and dispense a desired quantity and variety of roasted coffee beans. It is important that the dispenser be easy to use so that an untrained consumer has little trouble. The dispenser must also be mechanically simple so as to have long service life with little maintenance for the grocer or the distributor.
The dispenser must also be easy to refill with fresh roasted beans, and preferably allows the consumer to view the coffee bean while they are being stored. This is because the color and texture of the beans is an important indicator of quality that consumers wish to know before purchasing the roasted beans.
Coffee dispensers, as do all food dispensers, must be highly hygienic. This requirement dictates that the dispensers should be easy to disassemble so that they can be easily cleaned and sanitized. It is also desirable that the dispenser provide a metered amount of coffee beans so that the consumer does not need to measure the product after it is dispensed. If the consumer has to measure the product, some of the product will be discarded when too much is dispensed and the consumer may be upset if too little is dispensed. In the case of a sealed coffee bean hopper where the consumer does not have access to the bulk of the product, this waste can be significant. It is desirable for the dispenser to provide a controlled, repeatable, metered amount of coffee beans each time it is used.
The measurement problem is more difficult in the case of coffee beans than in the case of ground coffee because coffee beans vary in density depending on the particular roast or variety of bean being dispensed. In other words, a quarter pound of one variety may take up more volume than a quarter pound of another variety making it difficult to accurately dispense a fixed quantity.
Conventional coffee bean dispensers include a hopper for storing the coffee beans at atmospheric pressure. The hopper is usually sealed to prevent dust and other particular contamination of the beans in the hopper. At the base of the hopper is a valve. The simplest form of valve may be simply a sliding pane which opens and closes a window at the base of the hopper. The coffee beans are fed by gravity through the valve to a product container such as a bag. Alternatively, the valve may incorporate a metering device such that a predetermined volume of coffee beans are dispensed each time the valve is operated.
U.S. Pat. No. 2,116,300 issued to Campos on May 3, 1938 shows a coffee dispenser adapted for ground coffee. This dispenser uses a sealed hopper and a metering valve which dispenses a fixed amount of ground coffee into a drawer at the base of the dispenser. The dispenser stores the coffee at room temperature, and is adapted only for ground coffee.
U.S. Pat. No. 3,204,833 issued to Weitzner on Sep. 7, 1965 shows a coffee dispenser which is similar to the Campos dispenser, but is adapted to dispense from a can of coffee rather than using a refillable hopper. The Weitzner dispenser uses a similar valve assembly to provide a metered amount of ground coffee with each operation of the valve.
U.S. Pat. No. 3,735,899 issued to Rollinson on May 29, 1973 shows a dispenser for granulated products which allows a number of hoppers supported on a single base. Each of the hoppers has a rotating valve at the base for dispensing a metered amount of product from the hopper. Although the hoppers are sealed in the Rollinson dispenser, the product is stored at atmospheric pressure.
U.S. Pat. No. 4,569,463 issued to Pellegrino on Feb. 11, 1986 shows a measuring and dispensing apparatus for dispensing a predetermined amount of a material that is contained in a hopper. The structure also uses a rotating metering valve and a sealed hopper. Again, the sealed hopper stores the product at atmospheric pressure. The rotating valve assembly in the Pellegrino dispenser has a removable insert to vary the volume of the metering valve to dispense different amounts of product with each operation.
European patent application publication number 424,326 A1 by Santino Locati published on Apr. 24, 1991 shows a ground coffee dispenser which has a sealed loading hopper and two metering assemblies. The metering chamber has a movable wall which varies the size to allow the volume of the metering chamber to be easily changed. By varying the size of the metering chamber, controlled amounts of the coffee can be mixed together to provide a selected coffee blend.
A need remains for a coffee storage system and dispenser that stores coffee beans or other food product in a reduced pressure or vacuum environment. Alternatively, a need exists for a coffee bean storage system and dispenser which stores coffee beans in a nitrogen or inert gas environment with low moisture content. A need also exists for an air lock and valve system for easily removing coffee beans from a vacuum storage container. A further need exists for a metering system which is easily adjustable and yet allows the coffee beans to remain under vacuum while in the metering chamber.
3. Solution to the Problem
The above identified problems and others are solved by a flowable food product dispenser having a storage hopper or chamber that can be pressurized or held at reduced pressure or vacuum. The dispenser of the present invention includes a valve assembly that maintains the flowable food product in a vacuum until dispensed from the hopper. The dispenser includes a metering chamber with easily adjustable size for dispensing a controlled volume or weight of product from the hopper. A mechanism is provided for easily operating the valve assembly and metering device so that operation of the dispenser is simple.